Release assembly for a downhole tool string

Abstract

A release assembly ( 200 ) for releasing a portion of a tool string in a wellbore. The release assembly ( 200 ) includes an outer housing ( 202 ) having a fishing receptacle ( 206 ) disposed therein. The fishing receptacle ( 206 ) includes a fishing neck ( 208 ). A support assembly ( 214 ) is disposed within the housing ( 202 ). The support assembly ( 214 ) has a first position wherein the support assembly ( 214 ) engages the fishing neck ( 208 ) to prevent separation of the fishing receptacle ( 206 ) from the housing ( 202 ) and a second position wherein the support assembly ( 214 ) is disengaged from the fishing neck ( 208 ) no longer preventing separation of the fishing receptacle ( 206 ) from the housing ( 202 ). An actuator ( 224 ), disposed within the housing ( 202 ), maintains the support assembly ( 214 ) in the first position until actuation thereof allows the support assembly ( 214 ) to shift to the second position.

What is claimed is: 
     
       1. A release assembly for releasing a portion of a tool string in a wellbore, the release assembly comprising:
 an outer housing; 
 a fishing receptacle disposed within the housing, the fishing receptacle having a fishing neck; 
 at least one shearable member initially coupling the fishing receptacle to the outer housing; 
 a support assembly disposed within the housing, the support assembly having a first position wherein the support assembly engages the fishing neck to prevent relative axial movement between the fishing receptacle and the housing and a second position wherein the support assembly is disengaged from the fishing neck no longer preventing relative axial movement between the fishing receptacle and the housing; and 
 an actuator disposed within the housing, the actuator maintaining the support assembly in the first position until actuation thereof allows the support assembly to shift to the second position, 
 wherein, after shifting the support assembly to the second position, application of sufficient tension between the fishing receptacle and the outer housing will cause the at least one shearable member to shear, thereby decoupling the fishing receptacle and the outer housing. 
 
     
     
       2. The release assembly as recited in  claim 1  wherein the support assembly further comprise a plurality of rotatable jaws that engage the fishing neck when the support assembly is in the first position. 
     
     
       3. The release assembly as recited in  claim 2  wherein the actuator further comprises a solenoid and an actuator sleeve operably associated with the solenoid, the actuator sleeve engaging the rotatable jaws to maintain engagement of the rotatable jaws with the fishing neck until actuation of the solenoid shifts the actuator sleeve enabling rotation of the rotatable jaws out of engagement with the fishing neck. 
     
     
       4. The release assembly as recited in  claim 2  further comprising at least one sensor operable to identified a tension level in the release assembly. 
     
     
       5. The release assembly as recited in  claim 4  wherein the sensor further comprises a stain gauge. 
     
     
       6. A release assembly for releasing a portion of a tool string in a wellbore, the release assembly comprising:
 an outer housing; 
 a fishing receptacle disposed within the housing, the fishing receptacle having a fishing neck; 
 a mechanically actuated release member initially coupling the fishing receptacle to the outer housing; 
 a support assembly disposed within the housing, the support assembly having a first position wherein the support assembly engages the fishing neck to prevent relative axial movement between the fishing receptacle and the housing and a second position wherein the support assembly is disengaged from the fishing neck no longer preventing relative axial movement between the fishing receptacle and the housing; and 
 an electrically actuated release member disposed within the housing, the electrically actuated release member initially maintaining the support assembly in the first position until electrical actuation thereof allows the support assembly to shift to the second position, 
 wherein, after shifting the support assembly to the second position, mechanical actuation of the mechanically actuated release member decouples the fishing receptacle and the outer housing. 
 
     
     
       7. The release assembly as recited in  claim 6  wherein the support assembly further comprise a plurality of rotatable jaws that engage the fishing neck when the support assembly is in the first position. 
     
     
       8. The release assembly as recited in  claim 7  wherein the electrically actuated release member further comprises a solenoid and an actuator sleeve operably associated with the solenoid, the actuator sleeve engaging the rotatable jaws to maintain engagement of the rotatable jaws with the fishing neck until electrical actuation of the solenoid shifts the actuator sleeve enabling rotation of the rotatable jaws out of engagement with the fishing neck. 
     
     
       9. The release assembly as recited in  claim 6  further comprising at least one sensor operable to identified a tension level in the release assembly. 
     
     
       10. The release assembly as recited in  claim 9  wherein the sensor further comprises a stain gauge. 
     
     
       11. The release assembly as recited in  claim 6  wherein the mechanically actuated release member further comprises at least one shearable member. 
     
     
       12. The release assembly as recited in  claim 11  wherein the at least one shearable member further comprises at least one shear screw. 
     
     
       13. The release assembly as recited in  claim 6  wherein the mechanically actuated release member further comprises a plurality of shearable members. 
     
     
       14. The release assembly as recited in  claim 13  wherein the plurality of shearable members further comprises a plurality of shear screws. 
     
     
       15. The release assembly as recited in  claim 13  wherein the plurality of shearable members are circumferentially distributed about the outer housing. 
     
     
       16. A release assembly for releasing a portion of a tool string in a wellbore, the release assembly comprising:
 an outer housing; 
 a fishing receptacle disposed within the housing, the fishing receptacle having a fishing neck; 
 a first release member initially coupling the fishing receptacle to the outer housing; 
 a support assembly disposed within the housing, the support assembly having a first position wherein the support assembly engages the fishing neck to prevent relative axial movement between the fishing receptacle and the housing and a second position wherein the support assembly is disengaged from the fishing neck no longer preventing relative axial movement between the fishing receptacle and the housing; and 
 a second release member disposed within the housing, the second release member initially maintaining the support assembly in the first position until actuation thereof allows the support assembly to shift to the second position, 
 wherein, after shifting the support assembly to the second position, actuation of the first release member decouples the fishing receptacle and the outer housing. 
 
     
     
       17. The release assembly as recited in  claim 16  wherein the first release member and the second release member are actuated independent of one another. 
     
     
       18. The release assembly as recited in  claim 16  wherein the first release member and the second release member are actuated by different actuation modes. 
     
     
       19. The release assembly as recited in  claim 18  wherein the actuation mode of the second release member further comprises an electrical actuation mode. 
     
     
       20. The release assembly as recited in  claim 18  wherein the actuation mode of the first release member further comprises a mechanical actuation mode.